647 THE LEFT AND RIGHT RECURRENT LARYNGEAL NERVE LYMPH NODES POSSESS DIFFERENT ANATOMICAL CHARACTERISTICS AND RISK STRATIFICATIONS OF METASTASIS

Abstract

Abstract The left and right recurrent laryngeal nerve(RLN) are asymmetrical, and the precise differences and metastasis risk stratifications based on preoperative CT scan between the left and right RLN lymph nodes have not yet been analyzed. In this study, we compared the anatomical characteristics and generated prediction models to predict the probability of left and right RLN lymph node metastasis using preoperative clinical data in patients undergoing thoracolaparoscopic esophagectomy with cervical anastomosis to guide clinical treatment. Methods We retrospectively reviewed the clinical data of 1660 consecutive patients with thoracic esophageal cancer who underwent esophagectomy with cervical anastomosis at the Department of Thoracic Surgery at our center between January 2015 and December 2020 and investigated the anatomical characteristics and risks of bilateral RLN lymph nodes according to preoperative CT scan and pathological examination findings. Results A total of 299 and 343 patients who underwent left(right) RLN lymph node dissection were included in the final analysis. By plotting ROC curves, we concluded that the cutoff values of the long and short axis to predict metastasis of the left (right) RLN lymph nodes were 10 (8 mm) and 7.5 (6.5 mm), respectively. The short axis rather than the long axis was significantly associated with left RLN lymph node metastasis. Correspondingly, the long axis was much more important than the short axis in regard to the right RLN lymph nodes. Conclusion There were different anatomical characteristics and precise metastasis risk stratifications between the left and right RLN lymph node metastases.